Optically variable security features having covert forensic features

ABSTRACT

The invention relates to security feature for identification documents, and in particular to A security feature, comprising a first covert layer comprising a first covert material that is not visible to a human eye under except under a first condition, the first covert layer further comprising a material constructed and arranged to produce, upon an attempted intrusion into any part of the security feature, a first effect that is visible at least under the first condition; an optically variable layer having first and second sides, the first side being disposed adjacent the first covert layer, the optically varying layer being constructed and arranged to cover at least a portion of the first covert layer; and a second covert layer disposed adjacent to the second side of the optically variable layer, the second covert layer being constructed and arranged to cover at least a portion of the optically variable layer, the second covert layer comprising a second covert material that is visible to the human eye only at a second condition.

RELATED APPLICATION DATA

This application is related to the following U.S. patent applications:

Identification Document (Application No. 60/471,429, Attorney Docket No.P0833D, filed May 16, 2003, inventors Robert Jones, Brian Labrec,Daoshen Bi, and Thomas Regan).

Use of Pearlescent and Other Pigments to Create Security Documents(application Ser. No. 09/969,020, Attorney Docket No. P0537D, InventorsBentley Bloomberg and Robert L. Jones, filed Oct. 2, 2001).

Identification Card Printed With Jet Inks and Systems and Methods ofMaking Same (application Ser. No. 10/289,962, Attorney Docket No.P0708D, Inventors Robert Jones, Dennis Mailloux, and Daoshen Bi, filedNov. 6, 2002).

Contact Smart Cards Having a Document Core, Contactless Smart CardsIncluding Multi-Layered Structure, PET-Based Identification Document,and Methods of Making Same (application Ser. No. 10/329,318, AttorneyDocket No. P0711D, filed Dec. 23, 2002—Inventors Robert Jones, JosephAnderson, Daoshen Bi, Thomas Regan, and Dennis Mailloux,).

Ink with Cohesive Failure and Identification Document Including Same(application Ser. No. 10/329,315, Attorney Docket No. P0714D, filed Dec.23, 2002—Inventors Robert Jones and Bentley Bloomberg).

Laser Engraving Methods and Compositions, and Articles Having LaserEngraving Thereon (application Ser. No. 10/326,886, Attorney Docket No.P0724D, filed Dec. 20, 2002—Inventors Brian Labrec and Robert Jones).

Multiple Image Security Features for Identification Documents andMethods of Making Same (application Ser. No. 10/325,434, Attorney DocketNo. P028D, filed Dec. 18, 2002—Inventors Brian Labrec, Joseph Anderson,Robert Jones, and Danielle Batey).

Covert Variable Information on Identification Documents and Methods ofMaking Same (application Ser. No. 10/330,032, Attorney Docket No.P0732D, filed Dec. 24, 2002—Inventors: Robert Jones and Daoshen Bi).

Systems, Compositions, and Methods for Full Color Laser Engraving of IDDocuments (application Ser. No. 10/330,034, Attorney Docket No. P0734D,filed Dec. 24, 2002—Inventor Robert Jones).

Laser Etched Security Features for Identification Documents and Methodsof Making Same (application Ser. No. 10/330,033, Attorney Docket No.P0736D, filed Dec. 24, 2002—Inventors George Theodossiou and RobertJones).

Image Processing Techniques for Printing Identification Cards andDocuments (Application No. 10,411,354, Attorney Docket No. P0819D, filedApr. 9, 2003—Inventors Chuck Duggan and Nelson Schneck).

Identification Card Printer-Assembler for Over the Counter Card Issuing(application Ser. No. 10/436,729, Attorney Docket No. P0829D, filed May12, 2003—Inventors Dennis Mailloux, Robert Jones, and Daoshen bi).

Identification Document and Related Methods (Application No. 60/421,254,Attorney Docket No. P0703—Inventors: Geoff Rhoads, et al).

Identification Document and Related Methods (Application No. 60/418,762,Attorney Docket No. P0696—Inventors: Geoff Rhoads, et al).

Optically Variable Devices with Embedded Data for Authentication ofIdentity Documents (Application No. not yet assigned, Attorney DocketNo. P0816D, filed Mar. 31, 2003—Inventor Robert Jones).

Optically Variable Devices with Encrypted Embedded Data forAuthentication of Identity Documents (Application No. not yet assigned,Attorney Docket No. P0824D, filed Mar. 31, 2003—Inventors Robert Jonesand Leo Kenen).

Image Processing Techniques for Printing Identification Cards andDocument (Application No. 60/463,659 Attorney Docket No. P0825D, filedMar. 31, 2003—Inventors Robert Jones and Brian Labrec.

Each of the above U.S. Patent documents is herein incorporated byreference in its entirety. The present invention is also related to U.S.patent application Ser. No. 09/747,735, filed Dec. 22, 2000, Ser. No.09/602,313, filed Jun. 23, 2000, and Ser. No. 10/094,593, filed Mar. 6,2002, U.S. Provisional Patent Application No. 60/358,321, filed Feb. 19,2002, as well as U.S. Pat. No. 6,066,594. Each of the above U.S. Patentdocuments is herein incorporated by reference in its entirety.

Each of the above U.S. Patent documents is herein incorporated byreference in its entirety.

TECHNICAL FIELD

The present invention generally relates to identification and securitydocuments, and in particular, relates the formation a covert securityfeature such as a fluorescing, ultraviolet, infrared, thermachromicand/or optical variable feature on such documents.

BACKGROUND AND SUMMARY

Identification Documents

Identification documents (hereafter “ID documents”) play a critical rolein today's society. One example of an ID document is an identificationcard (“ID card”). ID documents are used on a daily basis—to proveidentity, to verify age, to access a secure area, to evidence drivingprivileges, to cash a check, and so on. Airplane passengers are requiredto show an ID document during check in, security screening and prior toboarding their flight. In addition, because we live in an ever-evolvingcashless society, ID documents are used to make payments, access anautomated teller machine (ATM), debit an account, or make a payment,etc.

(For the purposes of this disclosure, ID documents are broadly definedherein, and include, e.g., credit cards, bank cards, phone cards,passports, driver's licenses, network access cards, employee badges,debit cards, security cards, visas, immigration documentation, nationalID cards, citizenship cards, social security cards, security badges,certificates, identification cards or documents, voter registrationcards, police ID cards, border crossing cards, legal instruments,security clearance badges and cards, gun permits, gift certificates orcards, membership cards or badges, etc., etc. Also, the terms“document,” “card,” “badge” and “documentation” are used interchangeablythroughout this patent application.).

Many types of identification cards and documents, such as drivinglicenses, national or government identification cards, bank cards,credit cards, controlled access cards and smart cards, carry thereoncertain items of information which relate to the identity of the bearer.Examples of such information include name, address, birth date,signature and photographic image; the cards or documents may in additioncarry other variant data (i.e., data specific to a particular card ordocument, for example an employee number) and invariant data (i.e., datacommon to a large number of cards, for example the name of an employer).All of the cards described above will hereinafter be genericallyreferred to as “ID documents”.

As those skilled in the art know, ID documents such as drivers licensescan contain information such as a photographic image, a bar code (whichmay contain information specific to the person whose image appears inthe photographic image, and/or information that is the same from IDdocument to ID document), variable personal information, such as anaddress, signature, and/or birthdate, biometric information associatedwith the person whose image appears in the photographic image (e.g., afingerprint), a magnetic stripe (which, for example, can be on the aside of the ID document that is opposite the side with the photographicimage), and various security features, such as a security pattern (forexample, a printed pattern comprising a tightly printed pattern offinely divided printed and unprinted areas in close proximity to eachother, such as a fine-line printed security pattern as is used in theprinting of banknote paper, stock certificates, and the like).

An exemplary ID document can comprise a core layer (which can bepre-printed), such as a light-colored, opaque material (e.g., TESLIN(available from PPG Industries) or polyvinyl chloride (PVC) material).The core is laminated with a transparent material, such as clear PVC toform a so-called “card blank”. Information, such as variable personalinformation (e.g., photographic information), is printed on the cardblank using a method such as Dye Diffusion Thermal Transfer (“D2T2”)printing (described further below and also described in commonlyassigned U.S. Pat. No. 6,066,594, which is incorporated herein byreference in its entirety.) The information can, for example, comprisean indicium or indicia, such as the invariant or nonvarying informationcommon to a large number of identification documents, for example thename and logo of the organization issuing the documents. The informationmay be formed by any known process capable of forming the indicium onthe specific core material used.

To protect the information that is printed, an additional layer oftransparent overlaminate can be coupled to the card blank and printedinformation, as is known by those skilled in the art. Illustrativeexamples of usable materials for overlaminates include biaxiallyoriented polyester or other optically clear durable plastic film.

In the production of images useful in the field of identificationdocumentation, it may be desirable to embody into a document (such as anID card, drivers license, passport or the like) data or indiciarepresentative of the document issuer (e.g., an official seal, or thename or mark of a company or educational institution) and data orindicia representative of the document bearer (e.g., a photographiclikeness, name or address). Typically, a pattern, logo or otherdistinctive marking representative of the document issuer will serve asa means of verifying the authenticity, genuineness or valid issuance ofthe document. A photographic likeness or other data or indicia personalto the bearer will validate the right of access to certain facilities orthe prior authorization to engage in commercial transactions andactivities.

Identification documents, such as ID cards, having printed backgroundsecurity patterns, designs or logos and identification data personal tothe card bearer have been known and are described, for example, in U.S.Pat. No. 3,758,970, issued Sep. 18, 1973 to M. Annenberg; in GreatBritain Pat. No. 1,472,581, issued to G. A. O. Gesellschaft FurAutomation Und Organisation mbH, published Mar. 10, 1976; inInternational Patent Application PCT/GB82/00150, published Nov. 25, 1982as Publication No. WO 82/04149; in U.S. Pat. No. 4,653,775, issued Mar.31, 1987 to T. Raphael, et al.; in U.S. Pat. No. 4,738,949, issued Apr.19, 1988 to G. S. Sethi, et al.; and in U.S. Pat. No. 5,261,987, issuedNov. 16 1993 to J. W. Luening, et al. All of the aforementioneddocuments are hereby incorporated by reference.

Printing Information Onto ID Documents

The advent of commercial apparatus (printers) for producing dye imagesby thermal transfer has made relatively commonplace the production ofcolor prints from electronic data acquired by a video camera. Ingeneral, this is accomplished by the acquisition of digital imageinformation (electronic signals) representative of the red, green andblue content of an original, using color filters or other known means.Devices such as digital cameras, optical sensors, and scanners also canprovide digital image information. The digital image information isutilized to print an image onto a data carrier. For example, informationcan be printed using a printer having a plurality of small heatingelements (e.g., pins) for imagewise heating of each of a series of donorsheets (respectively, carrying diffuseable cyan, magenta and yellowdye). The donor sheets are brought into contact with an image-receivingelement (which can, for example, be a substrate) which has a layer forreceiving the dyes transferred imagewise from the donor sheets. Thermaldye transfer methods as aforesaid are known and described, for example,in U.S. Pat. No. 4,621,271, issued Nov. 4, 1986 to S. Brownstein andU.S. Pat. No. 5,024,989, issued Jun. 18, 1991 to Y. H. Chiang, et al.Each of these patents is hereby incorporated by reference.

Dye diffusion thermal transfer printing (“D2T2”) and thermal transfer(also referred to as mass transfer printing) are two printing techniquesthat have been used to print information on identification cards. Forexample, D2T2 has been used to print images and pictures, and thermaltransfer has been used to print text, bar codes, and single colorgraphics.

D2T2 is a thermal imaging technology that allows for the production ofphotographic quality images. In D2T2 printing, one or more thermallytransferable dyes (e.g., cyan, yellow, and magenta) are transferred froma donor, such as a donor dye sheet or a set of panels (or ribbons) thatare coated with a dye (e.g., cyan, magenta, yellow, black, etc.) to areceiver sheet (which could, for example, be part of an ID document) bythe localized application of heat or pressure, via a stylus or thermalprinthead at a discrete point. When the dyes are transferred to thereceiver, the dyes diffuse into the sheet (or ID card substrate), wherethe dyes will chemically be bound to the substrate or, if provided, to areceptor coating. Typically, printing with successive color panelsacross the document creates an image in or on the document's surface.D2T2 can result in a very high printing quality, especially because theenergy applied to the thermal printhead can vary to vary the dye densityin the image pixels formed on the receiver, to produce a continuous toneimage. D2T2 can have an increased cost as compared to other methods,however, because of the special dyes needed and the cost of D2T2ribbons. Also, the quality of D2T2-printed image may depend at least onan ability of a mechanical printer system to accurately spatiallyregister a printing sequence, e.g., yellow, magenta, cyan, and black.

Another thermal imaging technology is thermal or mass transfer printing.With mass transfer printing, a material to be deposited on a receiver(such as carbon black (referred to by the symbol “K”)) is provided on amass transfer donor medium. When localized heat is applied to the masstransfer donor medium, a portion (mass) of the material is physicallytransferred to the receiver, where it sits “on top of” the receiver. Forexample, mass transfer printing often is used to print text, bar codes,and monochrome images. Resin black mass transfer has been used to printgrayscale pictures using a dithered gray scale, although the image cansometimes look coarser than an image produced using D2T2. However, masstransfer printing can sometimes be faster than D2T2, and faster printingcan be desirable in some situations.

Printing of black (“K”) can be accomplished using either D2T2 or masstransfer. For example, black monochrome “K” mass transfer ribbonsinclude Kr (which designates a thermal transfer ribbon) and Kd (whichdesignates dye diffusion).

Both D2T2 and thermal ink have been combined in a single ribbon, whichis the well-known YMCK (Yellow-Magenta-Cyan-Black) ribbon (the letter“K” is used to designate the color black in the printing industry).Another panel containing a protectant (“P”) or laminate (typically aclear panel) also can be added to the YMCK ribbon).

Manufacture and Printing Environments

Commercial systems for issuing ID documents are of two main types,namely so-called “central” issue (CI), and so-called “on-the-spot” or“over-the-counter” (OTC) issue.

CI type ID documents are not immediately provided to the bearer, but arelater issued to the bearer from a central location. For example, in onetype of CI environment, a bearer reports to a document station wheredata is collected, the data are forwarded to a central location wherethe card is produced, and the card is forwarded to the bearer, often bymail. Another illustrative example of a CI assembling process occurs ina setting where a driver passes a driving test, but then receives herlicense in the mail from a CI facility a short time later. Still anotherillustrative example of a CI assembling process occurs in a settingwhere a driver renews her license by mail or over the Internet, thenreceives a drivers license card through the mail.

In contrast, a CI assembling process is more of a bulk process facility,where many cards are produced in a centralized facility, one afteranother. (For example, picture a setting where a driver passes a drivingtest, but then receives her license in the mail from a CI facility ashort time later. The CI facility may process thousands of cards in acontinuous manner.).

Centrally issued identification documents can be produced from digitallystored information and generally comprise an opaque core material (alsoreferred to as “substrate”), such as paper or plastic, sandwichedbetween two layers of clear plastic laminate, such as polyester, toprotect the aforementioned items of information from wear, exposure tothe elements and tampering. The materials used in such CI identificationdocuments can offer the ultimate in durability. In addition, centrallyissued digital identification documents generally offer a higher levelof security than OTC identification documents because they offer theability to pre-print the core of the central issue document withsecurity features such as “micro-printing”, ultra-violet securityfeatures, security indicia and other features currently unique tocentrally issued identification documents.

In addition, a CI assembling process can be more of a bulk processfacility, in which many cards are produced in a centralized facility,one after another. The CI facility may, for example, process thousandsof cards in a continuous manner. Because the processing occurs in bulk,CI can have an increase in efficiency as compared to some OTC processes,especially those OTC processes that run intermittently. Thus, CIprocesses can sometimes have a lower cost per ID document, if a largevolume of ID documents are manufactured.

In contrast to CI identification documents, OTC identification documentsare issued immediately to a bearer who is present at a document-issuingstation. An OTC assembling process provides an ID document“on-the-spot”. (An illustrative example of an OTC assembling process isa Department of Motor Vehicles (“DMV”) setting where a driver's licenseis issued to person, on the spot, after a successful exam.). In someinstances, the very nature of the OTC assembling process results insmall, sometimes compact, printing and card assemblers for printing theID document. It will be appreciated that an OTC card issuing process isby its nature can be an intermittent—in comparison to acontinuous—process.

OTC identification documents of the types mentioned above can take anumber of forms, depending on cost and desired features. Some OTC IDdocuments comprise highly plasticized poly(vinyl chloride) or have acomposite structure with polyester laminated to 0.5-2.0 mil (13-51.mu.m) poly(vinyl chloride) film, which provides a suitable receivinglayer for heat transferable dyes which form a photographic image,together with any variant or invariant data required for theidentification of the bearer. These data are subsequently protected tovarying degrees by clear, thin (0.125-0.250 mil, 3-6 .mu.m) overlaypatches applied at the printhead, holographic hot stamp foils(0.125-0.250 mil 3-6 .mu.m), or a clear polyester laminate (0.5-10 mil,13-254 .mu.m) supporting common security features. These last two typesof protective foil or laminate sometimes are applied at a laminatingstation separate from the printhead. The choice of laminate dictates thedegree of durability and security imparted to the system in protectingthe image and other data.

UV Security Features in ID Documents

One response to the problem of counterfeiting ID documents has involvedthe integration of verification features that are difficult to copy byhand or by machine, or which are manufactured using secure and/ordifficult to obtain materials. One such verification feature is the usein the card of a signature of the card's issuer or bearer. Otherverification features have involved, for example, the use of watermarks,biometric information, microprinting, covert materials or media (e.g.,ultraviolet (UV) inks, infrared (IR) inks, fluorescent materials,phosphorescent materials), optically varying images, fine line details,validation patterns or marking, and polarizing stripes. Theseverification features are integrated into an identification card invarious ways and they may be visible or invisible (covert) in thefinished card. If invisible, they can be detected by viewing the featureunder conditions which render it visible. At least some of theverification features discussed above have been employed to help preventand/or discourage counterfeiting.

Covert security features are those features whose presence is notvisible to the user without the use of special tools (e.g., UV or IRlights, digital watermark readers) or knowledge. In many instances, acovert security feature is normally invisible to a user. Sometechnologies that involve invisible features require the use ofspecialized equipment, such as a detector or a device capable of readingdigital watermarks. One type of covert security feature is the printingof information (images, designs, logos, patterns, text, etc.) in amaterial that is not visible under normal lighting conditions, but canbe viewed using a special non-visible light source, such as anultraviolet (UV) or infrared (IR) light source. Use of UV and/or IRsecurity features can be advantageous because although the devices (forexample, UV and/or IR light sources) required to see and use suchfeatures are commonly available at a reasonable cost, the ability tomanufacture and/or copy at least some implementations of such featuresis far less common and can be very costly. UV and IR based covertsecurity features thus can help deter counterfeiters because thefeatures cannot be copied by copiers or scanners and are extremelydifficult to manufacture without the requisite know-how, equipment, andmaterials.

For example, the assignee of the present invention has developed andmarketed a proprietary product called PolaPrime-UV™. PolaPrime-UV™ is atype of security feature. One application of PolaPrime-UV™ is for fullcolor photo quality printing of fixed (i.e., not variable data)fluorescent images. The artwork that can be printed using PolaPrime-UV™includes many images that can be produced with a combination of red,green, and blue phosphors. Under the appropriate light (e.g., a lightsource capable of providing UV light), the effect seen when viewing animage printed with PolaPrime-UV™ is similar in appearance to atelevision screen in that the image is formed by emission of lightrather than reflection as with ink on paper. To date, PolaPrime-UV™ hasbeen a reliable authenticator for genuine identification documents.

Printing of Covert Materials Such as UV

Many images, such as color images, are formed by subtractive techniques,e.g., light is passed through absorbing dyes and the combination of dyesproduce an image by sequentially subtracting cyan, magenta, and yellowcomponents to provide the full color image. In the case of a UVfluorescing image, the UV image is formed by light emitting fromfluorescing dyes or pigments as they are activated by a UV light orenergy source. A UV image can be imparted to an ID document via methodssuch as thermal transfer or D2T2.

Regardless of whether the UV materials are imparted via D2T2 or masstransfer panel, both panels produce transmissive images—the masstransfer panel produces a bitonal (e.g., two tones) image and the dyesublimation panel produces a monochromatic (or shaded) image.

Optically Variable and Tamper Evident Features

As color photocopiers and other similar imaging systems (e.g., scanners)have increased in quality, availability, and popularity, there has beena corresponding increase in the counterfeiting of security documentssuch as bank notes, passports and identification cards. Thus, issuersand creators of legitimate security documents have been attempting toadd security features to the documents that are difficult to obtainand/or difficult (or impossible) to photocopy or scan. Such securityfeatures can also serve to enhance the perceptions and resistance tosimulation of existing features on the security documents.

For example, it is known to provide on such security documents opticallyvariable features (which generally cannot which cannot be accuratelyreproduced by a photocopier or scanner because such features can beinvisible to, or viewed differently, by a photocopier. Because sometypes of photocopying processes reflect high energy light off anoriginal document containing the image to be copied, from a singleviewing angle, a security feature may have a different appearancedepending on angle at which it is viewed, or a different appearance inreflected and transmitted light.

Color shifting and other optically variable pigments, inks, dyes, andcolorants (collectively “optically variable media”) have a feature ofappearing to change color as the viewing angle of an observer changes(or as the angle of incident light striking the media changes).Optically variable media have been used on security documents, such asidentification cards, credit cards, checks, title document, currency,etc. The optically variable property provides several advantages whenused on security documents: (a) the presence and appearance of opticallyvariable quality provides another “check” or method to authenticate thesecurity document; (b) optically variable media are generally moredifficult for a layman to obtain and use properly, thus helping toprevent (or at least limit) forgery and to make forgeries and/oralteration easier to detect; and (c) photocopiers and scanners generallywill not reproduce most types of optically variable media, helping toreduce unauthorized reproduction or counterfeiting of such documents.Optically variable media also can be used with many other differenttypes of articles, such as consumer goods (e.g., toys, cars), paperproducts (e.g., greeting cards, magazines), and in the fine arts (e.g.,works of art).

Several methods exist to create optically variable media and to applysuch media to security documents. One method involves dispersing in amedium (e.g., paint or ink) a plurality of relatively small particles(typically flakes) that have specific optical properties. One example ofa particle is a particle comprising a plurality of thin film layers,each film having a particular color and/or optical property. Anotherexample of a particle that can have an optically varying appearance isdescribed in a commonly assigned patent application Ser. No. 09/969,020,entitled “Use of Pearlescent and Other Pigments to Create SecurityDocuments”, by Bentley Bloomberg and Robert L. Jones, filed Oct. 2, 2001(hereinafter “the '020 application”), the contents of which areincorporated by reference herein in their entirety.

The '020 application describes a media having optically variableproperties which includes, in one embodiment, particles comprising flat,irregularly shaped mica platelets coated with titanium dioxide and/oriron oxide. These particles, when dispersed in a media, can give agenerally “pearlescent” effect, with smaller particles producing a“satin” effect and larger particles producing a “glitter” effect. Inmany instances, optically variable media are incorporated into amaterial such as a laminate layer or overlaminate layer, providing anoptically variable indicia that overlays other information on the card.Generally, such an optically variable indicia contains “fixed” data(information that is the same from card to card).

Another method of providing optically variable materials is through theuse of certain types of liquid crystals. It is known that certain liquidcrystal materials exhibit a difference in color when viewed intransmission and reflection as well as an angularly dependent coloredreflection. A liquid crystal is a type of molecule that, when heatedabove its melting point, can enter a state that exhibits characteristicsof both isotropic melt and an ordered crystal. In the so-called liquidcrystal state, a liquid crystal molecule can be moving like a liquid butstill exhibit degrees of molecular order normally only found in solidcrystals. As a result, the liquid crystal can have some physicalproperties which are angle dependent in the liquid crystalline state,including refractive index. This can enable the liquid crystal to haveunique optical properties, including a varying appearance as the viewingangle changes, because of interference effects that cause reflection ofcertain spectral components of incident light and transmission of theremaining spectral components.

Liquid crystal materials have been incorporated into documents,identification cards and other security elements with a view to creatingdistinctive optical characteristics. U.S. Pat. No. 4,637,896 providesfurther information about polymeric liquid crystals, and the disclosureof this patent is hereby incorporated by reference.

It will be appreciated that the security of an identification documentwill be at least partially dependent upon the particular structure andproperties of the layers and the ease with which a successful intrusioncan be accomplished. In the case, for example, of the dyeimage-receiving element of the U.S. Pat. No. 4,738,949, there isproduced a monolithic ID card, by which is meant that the backgroundinformation and the photograph or other personalized information arecontained in the same layer. It is indicated in the patent (col. 2,lines 63-66) that, in this way, tampering with the photograph willdestroy the background information and forgeries can be prevented.

In U.S. Pat. No. 5,261,987, reference is made to the ID cards of theaforesaid U.S. Pat. No. 4,738,949 and to the lamination of a transparentlaminate (employing adhesive) onto the image-bearing surface. It isindicated that attempts to delaminate or peel apart the double compositelaminate caused the thermally-transferred dye image to be lifted off thepolycarbonate dye-receiver layer by virtue of the strong adhesionprovided by the adhesive. It is further disclosed that, in the case ofthe lamination between polyvinyl chloride sheets of a support sheetcarrying a polycarbonate surface having personalized and backgroundinformation thereon, the incorporation of the support sheet into the IDcard renders the card susceptible to being delaminated and altered.There is, thus, disclosed in U.S. Pat. No. 5,261,987 a method ofincreasing tamper resistance whereby personalized information is printed(by thermal dye transfer printing) onto the exposed surface of apolycarbonate receiver sheet and the polycarbonate receiving layer ofthe receiver element is then adhered and transferred to a cardstockmaterial pre-printed with background information.

Technologies exist that combine both optically variable properties andtamper evident properties. One example is a type of prefabricatedcoating of a liquid crystalline material that is available as theADVANTAGE product available from Advantage ID Technologies, Inc., ofLancaster, Pa., which is part of Applied Optical Technologies, plc, ofParkton, Md. and the United Kingdom. ADVANTAGE is an optically variablesecurity coating that can be used to protect documents, components,products, etc., from counterfeiting, alteration, and compromise.ADVANTAGE is provided in the form of security laminates (heat activated)and security labels. In at least one form, ADVANTAGE comprises apolymeric liquid crystal layer and a tamper evident layer.

Using the ADVANTAGE product, anti-counterfeiting substances can beembedded in the card or applied as a laminate, producing an image thatchanges color (in a trimodal manner, from transparent to orange togreen) as a card is tilted. This trimodal color change is difficult toimpossible for known copiers, scanners, and desktop publishing systemsto copy. The image itself can be designed to be easily seen by anunaided naked eye. If an attempt is made to tamper with a document towhich ADVANTAGE has been applied (e.g., as a security feature), chemicalcoatings that are part of the ADVANTAGE product fracture intomicrofragments, making it difficult to tamper with the security featurewithout destroying the security document to which it was applied or inwhich it was embedded. Often, evidence of such tampering can be seen byan unaided naked eye (or a naked eye aided by the use of an ultravioletlight source, if the tamper evident layer is a UV layer). In oneexample, the chemical coating is made from a material capable offluorescing under UV light, such that the fractured UV coating isvisible only under UV light.

Although it is known to use optically variable media on securitydocuments, use of such media can sometimes have limitations. Forexample, many optically variable media are substantially opaque, whichcan limit their application and use on particular types of securitydocuments, as well as the type and/or design of indicia that areprintable with such optically variable media. For example, the relativeopacity of many optically variable media means that an indicium (printedwith most optically variable media) that is intended to overlay otherinformation generally has an “open” type of design (such as a designwith widely spaced lines, or significant spaces between lines/dots), topermit information overlaid by the indicia to be substantiallyperceived.

Further, for some types of security document (e.g., drivers licenses,identification cards), the issuer wishes to provide a lot of informationin a relatively small card area. In particular, it often is desirable toprint information such as images of the bearer on a card. Such imagestypically are not “open” enough to be usable with most conventionaloptically variable media. Thus, applying an optically variable mediathat is opaque to such a card and printing an image with it means thatit can be difficult to put other information in that area that wasprinted/overlaid using the optically variable and still have thenon-optically variable information be perceivable to an unaided humaneye (for authentication or other purposes).

It also would be desirable to ensure that the optically variable featureis further protected by additional covert security elements that arevery difficult to obtain and to embed within the laminates of anidentification document. For example, infrared media, such as inks,pigments, and dyes, are invisible unless viewed using a special lightsource and also can be very difficult for a counterfeiter to obtain andto properly apply into identification documents, and would beadvantageous to use in a security feature application. Specific types ofultraviolet inks, which are “tuned” to fluoresce at only particularultraviolet light wavelengths, also can be advantageous in a securityfeature application. They also will be difficult to view without accessto and use of the particular light source. Use of such difficult toobtain media also can act as a forensic feature, because the sources forsuch media are limited and sales and access are often controlled, thusenabling an investigator to better identify the source of a giveninfrared, ultraviolet, or other covert media.

The ID document counterfeiter remains surprisingly resourceful.Improvements are needed to stay ahead of the counterfeiter. Onecounterfeiting technique involves a de-lamination attack. Consider an IDdocument that includes a printed substrate covered by a laminate layer.A de-lamination attack removes the laminate layer, sometimes with theaid of heat, to access information printed on the substrate. Oncerevealed, the counterfeiter can alter the printed information and reusethe substrate or laminate. It would be further desirable to be able toreadily detect whether such tampering and/or a forgery has occurred withrespect to an identification document and/or any indicia on it. Forexample, because variable indicia (e.g., a birthdate) is a frequenttarget of alteration and/or other types of fraud, it would be desirableif a security feature could be constructed and arranged so as to show ifan alteration attempt was made on a given indicia.

Some ID documents are susceptible to this type of attack. Consider theID document including a substrate, ink applied to the substrate (orlaminate layer) to convey information and a laminate layer covering theink and substrate. Conventional inks generally include a strong adhesionto either a document substrate or to a laminate. A counterfeiter can usethis design characteristic (adhesion) to his advantage. Uponde-lamination, the ink may adhere to the substrate layer or to alaminate layer. Regardless, the printed information is typicallypreserved on at least one layer and may be used again. (For example, ifthe ink adheres to a laminate, the counterfeiter can reuse the laminate.Or if the ink adheres to the substrate, the counterfeiter can perhapsalter the information by applying additional ink, or simply reuse theremaining information on the substrate.).

U.S. Pat. No. 5,380,695, herein incorporated by reference, discloses anidentification document designed to help deter intrusion attempts. Thispatent describes an image-receiving element that includes a support, apolymeric security layer including printing, and an image-receivinglayer. The polymeric security layer is designed such that its cohesivityis less than its adhesivity for each layer that is contiguous thereto. Aprinted security pattern is hopefully destroyed through partitioning ofthe security layer during an attempted de-lamination of theimage-receiving layer from the image-receiving element.

To provide these and other advantages, the invention described hereinproposes a unique security feature that combines an optically variablefeature, a forensic feature, and a tamper evident feature. On portion ofthe security feature is both visible and at least substantiallytranslucent in visible light, enabling it to be applied to virtually anyportion of an identification document, including being overlaid overother information on an identification document. At least one otherportion of the security feature is visible only in a light that is notvisible to the naked eye, such as UV or IR light. In one embodiment, thesecurity feature comprises a first covert layer, an optically variablelayer, and a second covert layer. The first covert layer comprises apatch of first material applied over a first side of the opticallyvariable layer, where the first material comprises a first covertmaterial that is visible to the naked eye only under at least onepredetermined light wavelength. The presence of the first covertmaterial is generally not known to the public. The optically variablelayer comprises a layer of material capable of presenting a varyingappearance depending on the angle from which the optically variablematerial is viewed. The second covert layer is disposed along a secondside of the optically variable layer and comprises a second layer of asecond covert material that breaks upon intrusion.

Advantageously, the security feature is overlaid at least partially overa variable indicia on the identification document. If an attempt is madeto delaminate or otherwise remove the security feature, a portion of thesecurity feature fractures, to provide tamper evidence.

In one embodiment the invention provides a security feature, comprisinga first covert layer, an optically variable layer, and a second covertlayer. The first covert layer comprises a first covert material that isnot visible to a human eye under except under a first condition. Thefirst covert layer further comprises a material constructed and arrangedto produce, upon an attempted intrusion into any part of the securityfeature, a first effect, such damaging breaking, cracking, rupturing,splitting, fracturing, splintering, changing color, changing texture,shattering, and destroying, that is visible at least under the firstcondition. The optically variable layer has first and second sides, thefirst side being disposed adjacent the first covert layer. The opticallyvarying layer is constructed and arranged to cover at least a portion ofthe first covert layer. The optically variable layer comprises anoptically variable material, such as a polymeric liquid crystal. Thesecond covert layer is disposed adjacent to the second side of theoptically variable layer. The second covert layer comprises a secondcovert material, such as an infrared, an ultraviolet, and/or athermachromic material, that is visible to the human eye only at asecond condition, such as at least one of predetermined wavelength oflight in the infrared range, a predetermined wavelength of light in theultraviolet range, and a predetermined temperature. The second covertlayer is constructed and arranged to cover at least a portion of theoptically variable layer.

In one embodiment, the first covert layer is operably coupled to theoptically variable layer and is constructed and arranged such that anattempted intrusion into the first covert layer causes damage to atleast one of the first covert layer and the optically variable layer. Inone embodiment, the first and second covert layers and the opticallyvariable layer are constructed and arranged such that an attemptedintrusion into the security feature causes damage to at least a portionof at least one layer of the first covert layer, second covert layer,and optically variable layer,.

In one embodiment, ADVANTAGE is used for at least one of the opticallyvariable layer and the first covert layer.

In another aspect, the invention provides an identification document,comprising a core layer, a security feature, and a first laminate layer.The core layer, which can, for example, be TESLIN, has first and secondsides. The security feature has first and second sides and has a firstside operably coupled to a first side of the core layer. The firstlaminate layer operably coupled to the second side of the securityfeature. The security feature comprises a first covert layer, a secondcovert layer, and an optically variable layer. The first covert layercomprises a first covert material that is not visible to a human eyeunder except under a first condition, the first covert layer furthercomprising a material constructed and arranged to produce a first effectthat is visible at least under the first condition upon an attemptedintrusion into the first covert layer. The optically variable layercomprises an optically variable material and has first and second sides,the first side being disposed adjacent the first covert layer, theoptically varying layer being constructed and arranged to cover at leasta portion of the first covert layer. The second covert layer is disposedadjacent to the second side of the optically variable layer, the secondcovert layer being constructed and arranged to cover at least a portionof the optically variable layer. The second covert layer comprises asecond covert material that is visible to the human eye only at a secondcondition.

In another embodiment, the invention provides method of making anidentification document. A first laminate layer having first and secondsides is provided. A first cover layer having first and second sides isdisposed adjacent to the first side of the first laminate layer. Thefirst side of an optically variable layer having first and second sidesis arranged adjacent to the second side of the first covert layer. Thefirst side of a second covert layer having first and second sides isplaced adjacent to the second side of the optically variable layer. Thefirst side of a core layer having first and second sides is aligned tothe second side of the second covert layer. The first laminate layer,first covert layer, optically variable layer, second covert layer, andcore layer are fixedly attached together. At least one indicium can beformed on the core layer.

In another embodiment, the invention provides a security feature,comprising a first layer of ADVANTAGE material, the first layer havingfirst and second sides and a layer of infrared material coating at leastthe first side of the ADVANTAGE material.

In still another aspect, the invention provides an identificationdocument, comprising a layer of ADVANTAGE material, the layer havingfirst and second sides, a core layer having first and second sides, alayer of adhesive material applied to at least the first side of thelayer of ADVANTAGE material and coupling at least a portion of theADVANTAGE material to the first side of the core layer, the adhesivematerial comprising an infrared material, and a substantiallytranslucent layer of laminate disposed at the second side of theADVANTAGE layer and along at least a portion of the first side of thecore layer, the laminate substantially sealing the layer of ADVANTAGE tothe core layer. In one embodiment of this aspect, the core layer furthercomprises an indicium formed thereon and wherein the layer of ADVANTAGEis positioned to overlay at least a portion of the indicium.

The foregoing and other features and advantages of the present inventionwill be even more readily apparent from the following DetailedDescription, which proceeds with reference to the accompanying drawingsand the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages, features, and aspects of embodiments of the inventionwill be more fully understood in conjunction with the following detaileddescription and accompanying drawings, wherein:

FIG. 1 is an illustration of an identification document in accordancewith a first embodiment of the invention;

FIGS. 2A-2F are illustrations of an enlarged top view of the securityfeature of the identification document of FIG. 1, under variousconditions;

FIG. 3 is an exploded cross sectional view of the identificationdocument of FIG. 1, taken along the line 1C-1C;

FIG. 4 is a cross sectional view of the identification document of FIG.1, taken along the line 1C-1C, showing the identification document fullyassembled;

FIG. 5 is a cross sectional view of the identification document of FIGS.1 and 4 showing the path along which an intrusion is made into theidentification document;

FIG. 6 is a cross section view of the identification document of FIGS.1, 4, and 5 after the intrusion to the identification document has beenmade, showing the fracturing of the security feature;

FIG. 7 is an illustrative diagram of a first central issue cardproduction system that can be used to produce the ID document of FIG. 1,in accordance with one embodiment of the invention;

FIG. 8 is an illustration of a portion of a laminate roll usable withthe system of FIG. 7, showing a laminate with security patches formedthereon;

FIG. 9 is a flow chart of a first method for manufacturing the IDdocument of FIG. 1 using the system of FIG. 7, in accordance with oneembodiment of the invention;

FIG. 10 is an illustrative diagram of a second central issue cardproduction system that can be used to produce the ID document of FIG. 1,in accordance with one embodiment of the invention; and

FIG. 11 is a flow chart of a second method for manufacturing the IDdocument of FIG. 1 in the card production system of FIG. 10.

Of course, the drawings are not necessarily drawn to scale, withemphasis rather being placed upon illustrating the principles of theinvention. In the drawings, like reference numbers indicate likeelements or steps. Further, throughout this application, certainindicia, information, identification documents, data, etc., may be shownas having a particular format, arrangement, shape, outline, crosssectional shape, etc., (e.g., rectangular, elliptical) but that isprovided by way of example and illustration only and is not limiting,nor is any format, arrangement, shape, outline, cross sectional shape,etc, intended to represent any actual resultant format, arrangement,shape, outline, cross sectional shape, etc, that occurs duringmanufacturing of identification documents.

DETAILED DESCRIPTION

Terminology

In the foregoing discussion, the use of the word “ID document” isbroadly defined and intended to include all types of ID documents,including (but not limited to), documents, magnetic disks, credit cards,bank cards, phone cards, stored value cards, prepaid cards, smart cards(e.g., cards that include one more semiconductor chips, such as memorydevices, microprocessors, and microcontrollers), contact cards,contactless cards, proximity cards (e.g., radio frequency (RFID) cards),passports, driver's licenses, network access cards, employee badges,debit cards, security cards, visas, immigration documentation, nationalID cards, citizenship cards, social security cards, security badges,certificates, identification cards or documents, voter registrationand/or identification cards, police ID cards, border crossing cards,security clearance badges and cards, legal instruments, gun permits,badges, gift certificates or cards, membership cards or badges, andtags. Also, the terms “document,” “card,” “badge” and “documentation”are used interchangeably throughout this patent application.). In atleast some aspects of the invention, ID document can include any item ofvalue (e.g., currency, bank notes, and checks) where authenticity of theitem is important and/or where counterfeiting or fraud is an issue.

In addition, in the foregoing discussion, “identification” at leastrefers to the use of an ID document to provide identification and/orauthentication of a user and/or the ID document itself. For example, ina conventional driver's license, one or more portrait images on the cardare intended to show a likeness of the authorized holder of the card.For purposes of identification, at least one portrait on the card(regardless of whether or not the portrait is visible to a human eyewithout appropriate stimulation) preferably shows an “identificationquality” likeness of the holder such that someone viewing the card candetermine with reasonable confidence whether the holder of the cardactually is the person whose image is on the card. “Identificationquality” images, in at least one embodiment of the invention, includecovert images that, when viewed using the proper facilitator (e.g., anappropriate light or temperature source), provide a discernable imagethat is usable for identification or authentication purposes.

There are a number of reasons why an image or information on an IDdocument might not qualify as an “identification quality” image. Imagesthat are not “identification quality” may be too faint, blurry, coarse,small, etc., to be able to be discernable enough to serve anidentification purpose. An image that might not be sufficient as an“identification quality” image, at least in some environments, could,for example, be an image that consists of a mere silhouette of a person,or an outline that does not reveal what might be considered essentialidentification essential (e.g. hair or eye color) of an individual.

Of course, it is appreciated that certain images may be considered to be“identification quality” if the images are machine readable orrecognizable, even if such images do not appear to be “identificationquality” to a human eye, whether or not the human eye is assisted by aparticular piece of equipment, such as a special light source. Forexample, in at least one embodiment of the invention, an image or dataon an ID document can be considered to be “identification quality” if ithas embedded in it machine-readable information (such as digitalwatermarks or steganographic information) that also facilitateidentification and/or authentication.

Further, in at least some embodiments, “identification” and“authentication” are intended to include (in addition to theconventional meanings of these words), functions such as recognition,information, decoration, and any other purpose for which an indicia canbe placed upon an article in the article's raw, partially prepared, orfinal state. Also, instead of ID documents, the inventive techniques canbe employed with product tags, product packaging, business cards, bags,charts, maps, labels, etc., etc., particularly those items includingmarking of an laminate or over-laminate structure. The term ID documentthus is broadly defined herein to include these tags, labels, packaging,cards, etc.

“Personalization”, “Personalized data” and “variable” data are usedinterchangeably herein, and refer at least to data, images, andinformation that are “personal to” or “specific to” a specificcardholder or group of cardholders. Personalized data can include datathat is unique to a specific cardholder (such as biometric information,image information, serial numbers, Social Security Numbers, privileges acardholder may have, etc.), but is not limited to unique data.Personalized data can include some data, such as birthdate, height,weight, eye color, address, etc., that are personal to a specificcardholder but not necessarily unique to that cardholder (for example,other cardholders might share the same personal data, such asbirthdate). In at least some embodiments of the invention,personal/variable data can include some fixed data, as well. Forexample, in at least some embodiments, personalized data refers to anydata that is not pre-printed onto an ID document in advance, so suchpersonalized data can include both data that is cardholder-specific anddata that is common to many cardholders. Variable data can, for example,be printed on an information-bearing layer of the ID card using thermalprinting ribbons and thermal printheads.

The terms “indicium” and indicia as used herein cover not only markingssuitable for human reading, but also markings intended for machinereading. Especially when intended for machine reading, such an indiciumneed not be visible to the human eye, but may be in the form of amarking visible only under infra-red, ultra-violet or other non-visibleradiation. Thus, in at least some embodiments of the invention, anindicium formed on any layer in an identification document (e.g., thecore layer) may be partially or wholly in the form of a marking visibleonly under non-visible radiation. Markings comprising, for example, avisible “dummy” image superposed over a non-visible “real” imageintended to be machine read may also be used.

“Laminate” and “overlaminate” include (but are not limited to) film andsheet products. Laminates usable with at least some embodiments of theinvention include those which contain substantially transparent polymersand/or substantially transparent adhesives, or which have substantiallytransparent polymers and/or substantially transparent adhesives as apart of their structure, e.g., as an extruded feature. Examples ofusable laminates include at least polyester, polycarbonate, polystyrene,cellulose ester, polyolefin, polysulfone, or polyamide. Laminates can bemade using either an amorphous or biaxially oriented polymer as well.The laminate can comprise a plurality of separate laminate layers, forexample a boundary layer and/or a film layer.

“Optically variable” includes (but is not limited to) coatings, films,devices, foils, threads, etc., that exhibit a varying appearancedepending on, e.g., the angle at which they are viewed, the type oflight that is used to view the device (e.g., reflective light versustransmissive light, visible versus non-visible, etc). For example,so-called “color shifting” films, laminates, coatings, particles,threads, etc., which appear to have a first color (or set of colors, orlack of color(s)) when viewed at a first angle (or first type of light)and a different color (or set of colors, or lack of color(s)) whenviewed at a second angle (or type of light) can all be said to beoptically variable. Holograms KINEGRAMS (available from Kurz OVDKinegram in Switzerland), Exelgrams (available from CSIRO of Australia),PolaSecure™ (available from the assignee of the present invention),ADVANTAGE, and Tri-Color Polasecure™ (also available from the assigneeof the present invention) are additional examples of materials that areoptically variable. The materials described in the aforementioned '020application also are materials that are optically variable.

The degree of transparency of the laminate can, for example, be dictatedby the information contained within the identification document, theparticular colors and/or security features used, etc. The thickness ofthe laminate layers is not critical, although in some embodiments it maybe preferred that the thickness of a laminate layer be about 1-20 mils.Lamination of any laminate layer(s) to any other layer of material(e.g., a core layer) can be accomplished using any conventionallamination process, and such processes are will-known to those skilledin the production of articles such as identification documents. Ofcourse, the types and structures of the laminates described herein areprovided only by way of example, those skilled in the art willappreciated that many different types of laminates are usable inaccordance with the invention.

For example, in ID documents, a laminate can provide a protectivecovering for the printed substrates and provides a level of protectionagainst unauthorized tampering (e.g., a laminate would have to beremoved to alter the printed information and then subsequently replacedafter the alteration.). Various lamination processes are disclosed inassignee's U.S. Pat. Nos. 5,783,024, 6,007,660, 6066594, and 6,159,327.Other lamination processes are disclosed, e.g., in U.S. Pat. Nos.6,283,188 and 6,003,581. Each of these U.S. Patents is hereinincorporated by reference.

The material(s) from which a laminate is made may be transparent, butneed not be. Laminates can include synthetic resin-impregnated or coatedbase materials composed of successive layers of material, bondedtogether via heat, pressure, and/or adhesive. Laminates also includessecurity laminates, such as a transparent laminate material withproprietary security technology features and processes, which protectsdocuments of value from counterfeiting, data alteration, photosubstitution, duplication (including color photocopying), and simulationby use of materials and technologies that are commonly available.Laminates also can include thermosetting materials, such as epoxy.

For purposes of illustration, the following description will proceedwith reference to ID document structures (e.g., TESLIN-core,multi-layered ID documents) and fused polycarbonate structures. Itshould be appreciated, however, that the present invention is not solimited. Indeed, as those skilled in the art will appreciate, theinventive techniques can be applied to many other structures formed inmany different ways. For example, in at least some embodiments, theinvention is usable with virtually any product, especially articles towhich a film, laminate and/or coating is applied, including articlesformed from paper, wood, cardboard, paperboard, glass, metal, plastic,fabric, ceramic, rubber, along with many man-made materials, such asmicroporous materials, single phase materials, two phase materials,coated paper, synthetic paper (e.g., TYVEC, manufactured by Dupont Corpof Wilmington, Del.), foamed polypropylene film (including calciumcarbonate foamed polypropylene film), plastic, polyolefin, polyester,polyethylenetelphthalate (PET), PET-G, PET-F, and polyvinyl chloride(PVC), and combinations thereof.

We also anticipate that the invention will have applicability to anydocument, article of manufacture or any situation or service in which itis desirable to trace the source of an article, document, or product(especially a counterfeit or altered product) and/or to detect tamperingwith an article, document, or product. Examples include (but are notlimited to) pharmaceutical and drug products (especially packaging),foodstuffs, so-called “gray market” goods, imported goods of all kinds,copies of software, movies, and other media stored on compact disks(CD's) and/or digital versatile disks (DVDs), etc.

Referring now to FIG. 1, we illustrate of an identification document 100in accordance with a first embodiment of the invention. Theidentification document 100 includes fixed indicia 106, security feature110, first variable indicia 114 (e.g. variable personal information,such as address and birthdate), second variable indicia 114′ (e.g., aphotographic image of the bearer of the card, which image can bedigitized and/or contain a digital watermark or other encoding), ghostimage 122, biometric indicia 124 associated with the bearer of the card(which indicia is shown for illustrative purposes only to be afingerprint, but which could be any biometric indicia, includinginformation relating to retinal pattern, iris, hand geometric, templatefor facial recognition, etc), bar code 130 (which may containinformation specific to the person whose image appears in the secondvariable indicia 114′ and/or information that is the same from IDdocument to ID document), and signature 132. Although not illustrated inFIG. 1, the ID document 100 can include a magnetic stripe (which, forexample, can be on the rear side (not shown) of the ID document 100),and various security features other than security feature 10, such as ahologram, security pattern printed in the background (for example, aprinted pattern comprising a tightly printed pattern of finely dividedprinted and unprinted areas in close proximity to each other, such as afine-line printed security pattern as is used in the printing ofbanknote paper, stock certificates, and the like) and/or a securitypattern printed an overlaminate, etc.

The security feature 110 of FIG. 1, in one embodiment of the invention,comprises an optically variable, tamper indicating, covert, andforensically protected feature that is applied to a predeterminedlocation of the identification document prior to or coincident withapplication of the final layer of laminate (e.g., overlaminate) to theidentification document. In FIG. 1, two security features 110 are shown:one security feature 110 is illustrated as at least partially overlayingvariable indicia 114 (namely, at the location of the birthdate) and theother security feature 110 is illustrated as at least partiallyoverlaying variable indicia 114′ (namely, the portrait of the bearer).It can be advantageous to locate the security feature 110 so that it isdisposed on a location of the identification document 100 which is alikely target for tampering, forgery, and/or alteration, such as alocation of variable indicia 114, 114′, as is illustrated in FIG. 1.

The view of the security feature 110 in FIG. 1 is at an angle when thesecurity feature 110 is substantially clear (as will be explainedfurther below). It is also a view when the covert layer 112 (see FIGS. 2and 3) of security feature 110 of the identification document 110 isappropriately stimulated so as to become visible. These views areexplained further below.

FIG. 2A is an enlarged close up view of the security feature 110 of FIG.2 at a predetermined viewing angle, showing that the security feature110 comprises a first covert layer 112, an optically variable layer 116,and a second covert layer 118. In this embodiment, the second covertlayer 118 is transparent enough to permit the optically variable layer116 to be visible (at appropriate viewing angles) to a naked eye, and topermit the first covert layer 112 to be visible under a conditionappropriate to the given covert pigment in the layer 112 (e.g., underthe appropriate frequency(ies) of light if the pigment in the firstcovert layer 112 is responsive to UV and/or IR light, at the appropriatetemperature if the pigment in the first covert layer is thermachromic,etc.).

For illustrative purposes, the first covert layer 112 is shown in thisview as if it is being stimulated by an appropriate stimulus (e.g., UVlight). Additional views are shown and described in connection withFIGS. 2B-2F. In the embodiment of FIG. 2A, the optically variable layer116 actually covers the first covert layer 112 and would actually“overlay” even a stimulated first covert layer 112, although such aquality is difficult to illustrate in FIG. 2A.

FIGS. 2B-2D illustrate the security feature 110 of FIGS. 1 and 2 atfirst, second, and third viewing angles, respectively. At the firstviewing angle of FIG. 2B, the optically variable layer 116 is visible asa first color (illustrated by the series of horizontal lines), showing afirst series of numbers 113 in a first color. At the second viewingangle of FIG. 2C, the optically variable layer 116 is visible as asecond color (illustrated by the series of cross hatched lines) and thefirst series of numbers 113 is a second color. In an advantageousembodiment, the first color and the second color are two colors that aredistinguishable from each other and visible to the naked eye, such as(e.g.), orange and green. At the third viewing angle of FIG. 2C, theoptically variable layer 116 appears to be “clear” to the naked eye (italso can be a third color, such as blue) (note that the “clear” viewingangle was used to illustrate the security feature 110 in FIG. 1). At theclear viewing angle the series of numbers 113 is not visible.

FIG. 2E illustrates the security feature 110 at a first viewing angleand without appropriate stimulation to enable the covert layer 112 to bevisible (e.g., without viewing the security feature 110 usingpredetermined wavelength(s) of UV or IR light, appropriate temperature,etc.) of the first covert layer 112. FIG. 2F illustrates the securityfeature 110 of FIG. 2E after application of the appropriate stimulation(i.e., viewed using appropriate wavelength of UV light, IR light,appropriate temperature, etc., as applicable. As FIG. 2F illustrates,the first covert layer 112 becomes visible with the appropriatestimulation.

FIG. 3 is an exploded cross sectional view of the identificationdocument 100 of FIG. 1, taken along the line 1C-1C, and FIG. 4 is across sectional view of the identification document of FIG. 1, takenalong the line 1C-1C, showing the identification document fullyassembled. The security feature 110 is indicated in both FIGS. 2 and 4by the dotted line. The embodiment of FIG. 4 illustrates that, afterlamination, the adhesive 120 and transparent (or translucent) laminate134 are substantially co-mingled, but those skilled in the art willunderstand that it is not required that the adhesive 120 and laminate134 be mixed.

Referring to FIGS. 3 and 4, the core layer 102 is constructed andarranged to have fixed indicia 106 and variable indicia 114, 114′ formedthereon. Those skilled in the art will appreciate that there arenumerous known ways to form indicia on a security document, includingbut not limited to indigo (variable offset) laser xerography (variableprinting), offset printing (fixed printing), D2T2, mass transfer,inkjet, and/or laser engraving, etc., and those methods are not detailedfurther here. Further, those skilled in the art will appreciate thatcertain core materials are more suitable for particular methods offorming indicia. For example, depending on the technique for formingindicia, core materials such as polycarbonate, TESLIN, TYVEC, MYLAR,MELINEX, polyolefin, polyester, polycarbonate, polystyrene, celluloseester, polyolefin, polysulfone, polyvinyl chloride (PVC), polyethylene,polypropylene, and polyamide, amorphous polymer, and biaxially orientedpolymer can be used to form the core material.

For purposes of illustration in this embodiment, it is assumed that thefixed indicia 106 and variable indicia 114, 114′ are formed as part of acentral issue process using a method such as indigo or laser xerography.It also is assumed that the core 102 comprises a substantially opaquematerial suitable for indigo or laser xerography printing thereon, suchas a silica filled polyolefin like TESLIN.

Referring again to FIG. 3, the first covert layer 112 is a layer that is“breakable” (i.e., that becomes damaged) upon intrusion. Methods andmaterials for making such layers are known; see, e.g., U.S. Pat. No.4,890,763, the contents of which are hereby incorporated by reference.The first covert layer 112 also comprises one or more pigments that arenot normally visible to a human eye in ambient light conditions. Such apigment can comprise, for example, ultraviolet pigments, infraredpigments, and/or thermachromic pigments. It is noted that damage to thecovert layer 112 (such as results from an intrusion or an attemptedintrusion) may only be visible when the appropriate conditions exist(e.g., light wavelength or temperature) that would permit the covertlayer 112 to be visible to the human eye. In the embodiment, of FIGS. 1and 3, the covert layer is shown for illustrative purposes only to havea rectangular shape; that shape is not, of course, limiting. The covertlayer 112 can be structured and arranged to have any shape or formand/or to convey information, such as an indicium, if desired. In oneadvantageous embodiment, the covert layer 112 comprises an ultravioletpigment.

Alternately, the covert layer 112 can comprise an tamper evidentmaterial capable of becoming damaged upon intrusion and which is itselfsubstantially visible in ambient light, but which is coated with asufficient quantity of material (e.g., an ultraviolet or infrared dye)that is itself not visible in ambient light to, render the covert layer112 itself substantially invisible in ambient light.

The optically variable layer 116 comprises a layer of material that hasa first appearance at a first angle of viewing and a second appearanceat a second angle of viewing. The varying appearance can, for example,be a varying color (as shown in FIG. 2). In one embodiment, theoptically variable layer 116 comprises a polymeric liquid crystalmaterial. Other optically variable materials and devices, such as inks,pigments, holograms, the materials disclosed in the aforementioned '020application, etc., also may be usable. As is shown in FIG. 3, theoptically variable layer covers at least one side of the first covertlayer 112.

In one advantageous embodiment, it is possible to provide both the firstcovert layer 112 and the optically variable layer 116 by using a portionof the aforementioned ADVANTAGE security material. As those skilled inthe art will appreciate, the ADVANTAGE material can be provided toidentification documents in numerous ways, including as part of a patch,as a coating, as a label, as a seal, as a film, on a tape, etc.

Referring again to FIG. 3, a second covert layer 118 is applied over theoptically variable layer 116 (or over the portion of ADVANTAGEmaterial). In one embodiment, the second covert layer 118 comprises asubstantially translucent film containing a second covert pigment thatis substantially invisible to the naked eye in ambient light and/orambient temperature conditions. The second covert layer 118 also can be,in one embodiment, a coating. In one embodiment, the second covert layer118 is made using polyester material, such as the polyester materialsand powder coatings generally available from Rohm Haas Corporation ofFlying Hills, Pa. In an advantageous embodiment, the second covert layer118 is selected to have an adhesion to both the core 102 and to aportion of ADVANTAGE material. The second covert layer 118 can also bemade from any material capable of forming a coating on the selectedoptically variable layer 116 (or on the ADVANTAGE layer, if theembodiment is using the ADVANTAGE product), including polyester,polyolefin, polyethylene, polypropylene, polycarbonate, etc. The secondcovert layer 118 further comprises a second covert material, such as aninfrared pigment, an ultraviolet pigment, or a thermachromic pigment.The second covert material is a material that becomes visible underappropriate stimulation.

For example, in one embodiment, the second covert material is aninfrared ink or dye that fluoresces at one or more predeterminedwavelengths of infrared light to produce an infrared feature. Use ofinfrared for security purposes is known. For example, Krutak et al.describe the use of near infrared fluorescent (NIRF) compounds used inpolyester-based and polyester-amide based coatings and ink compositionswhich are used for marking articles for identification/authenticationpurposes, in U.S. Pat. No. 5,292,855 issued Mar. 8, 1994, U.S. Pat. No.5,423,432, issued Jun. 13, 1995, and U.S. Pat. No. 5,336,714, issuedAug. 9, 1994. Krutak et al. also disclose tagging thermoplasticcontainers and materials with near infrared fluorescent compounds inU.S. Pat. No. 5,461,136 issued Oct. 24, 1995, U.S. Pat. No. 5,397,819,issued Mar. 14, 1995, and U.S. Pat. No. 5,703,229, issued Dec. 30, 1997.The use of near infrared fluorescent compounds as a security ink inthermal transfer printing has also been disclosed in Internationalapplication WO 97/32733, published Sep. 12, 1997, wherein an image isformed by thermally transferring ink from a ribbon to paper. Thedisclosures of these patents and applications are hereby incorporated byreference.

Doing this can provide several advantageous embodiments of theinvention. To improve security, knowledge of the presence of the secondcovert material can be kept from all but a few personnel and not knownto the general public. This can help to make counterfeit identificationdocuments (which may not contain the infrared feature) easier to detect.In addition, such an infrared dye is can be formulated to respond onlyto a very specific wavelength and/or intensity of infrared light (e.g.,to respond only to a “secret” frequency or intensity of infrared light.This can help to further thwart even the counterfeiter who learns thatinfrared is being used on the security feature 10, but does not knowthat the infrared must be formulated to respond to a particularintensity and/or wavelength of infrared light. The second covertmaterial 118 can even be formulated with an infrared ink or dye suchthat it is responsive only to a particular wavelength and/or intensityof infrared light. This may help to thwart a counterfeiter who attemptsto use a broad spectrum infrared ink or dye.

Another advantage of embodiments that use infrared inks or dyes is thatthe availability of such infrared inks and dyes is more limited than formany other types of so-called “covert” inks and dyes (e.g., more limitedthan UV or thermachromic inks/dyes). Those skilled in the art are awareof the sources for infrared inks and dyes (many sources of which willsell their product only to authorized users). One source for infraredinks and dyes usable with at least some embodiments of the invention isHoneywell Corporation. Another source for infrared inks and dyes usablewith at least some embodiments of the invention is any of the companiesauthorized to provide the infrared feature for the Euro currency thatthat became available in about 2003. By carefully controlling access andavailability, responsive wavelength, responsive intensity, or othercharacteristics, the infrared pigment also can provide forensicadvantages, especially in helping to detect and/or track counterfeitdocuments.

Those skilled in the art will appreciate that other types of covertpigments (e.g., UV and/or thermachromic inks and dyes) can be formulatedand controlled in the same manner described above in connection withinfrared pigments. It also will be appreciated that one or more covertpigments can be combined in any of the covert layers of theidentification document 100.

Referring again to FIGS. 3 and 4, in one embodiment, a layer of adhesive120 secures the security feature 110 to a layer of laminate 134 (whichcan be transparent or translucent, as desired). In one embodiment, thelaminate 134 is biax polyester and the adhesive is a polyethylenic basedhot melt adhesive. As will be described further below, affixing thesecurity feature 110 to the layer of laminate 134 can simplifymanufacture of the identification document 100 in some types ofenvironments (e.g., some types of central issue type environments).However, it will be understood by those skilled in the art that thesecurity feature 110 could be provided to the identification document ina number of other ways. For example, in one embodiment, the securityfeature 110 can be affixed first to the core 102, then the layer oflaminate 134 (with or without adhesive 120) can be affixed over it, tolaminate the security feature 110 to the identification document 100. Inone embodiment, the security feature 110 is “stamped” on to the core 102prior to lamination. In another embodiment, the separate components ofthe security feature 110 (e.g., first covert layer 112, opticallyvariable layer 116, and second covert layer 118) can be separatelyprovided and attached to the identification document 100, as part of themanufacture process. We even anticipate that the security feature 110could be embedded within an aperture formed on the core 102, if desired.

In a further embodiment of the invention (not shown), the securityfeature 110 can further include additional covert features. For example,in one embodiment, the security feature 110 further comprises a covertfeature that is hidden to the naked eye but visible using a commerciallens or using special software processing to simulate such a lens. Inanother embodiment, the security feature 110 further comprises aso-called “scrambled indicia” or “security indicia”. Such indiciaincorporates words or symbols that are concealed on a document andappear only when a specially grooved plastic viewer is moved across it.In a further embodiment, the security feature 110 further comprisesmicrotaggants (either visible or non-visible), such as microscopicparticles are color-coded, traceable, and traceable. Those skilled inthe art will appreciate that virtually any type of additional securityelements or features, whether covert or overt, can be incorporated intothe security feature 110 of the invention.

As illustrated by FIGS. 5 and 6, in accordance with one embodiment ofthe invention, an attempt to intrude into the security feature 110 (suchas might accompany an attempt to alter the variable indicia 114′) willresult in a partial or total destruction of the security feature 110 ina manner that is substantially irreparable and which can makesubstitution or alteration of the security feature to be detectable. InFIG. 5, the dotted line 132 shows, for illustrative purposes only, apath or breakage in the security feature 110 (this particular path ofbreakage is not, of course, limiting). As FIG. 6 indicates, the path ofbreakage effectively destroys the security feature 110. The opticallyvariable layer 118, for example, is broken into at least two portions116′ and 116″. Likewise, the second covert layer 118 is broken into atlast two portions 118′ and 118″. In this illustration, the first covertlayer 112 (which is a tamper evident layer) is illustrated also asbreaking into two portions 112′, and 112″, but it will further beappreciated that the first covert layer 112 can be formulated to“shatter” or substantially fall apart into a plurality of pieces notshown here.

As shown in FIGS. 5 and 6, the pattern of breakage of the securityfeature helps to ensure that an attempt to falsify, replace, or “repair”the security feature 110 is likely to be detected, as well, for severalreasons, including that (1) the optically variable feature is extremelydifficult to replicate and is unlikely to appear the same after breakageand attempted reconnection; and (2) because of the presence of covertelements present in the security feature 110 (e.g., infrared pigments insecond covert layer 118) which are not likely to be properly present ina falsified security feature, it becomes easier to detect forgeries.

As noted previously, there are a number of different ways to manufacturean identification document 100 that incorporates the security feature110 described herein. FIG. 7 is an illustrative diagram of a firstcentral issue card production system that can be used to produce theidentification document 110. In the system 500′ of FIG. 7, the securityfeature is formed on a roll of laminate in advance, prior to thelaminating of the laminate 134 to the core 102. See, for example, FIG.8, which is an illustration of a portion of a laminate roll 800 showinga laminate with security features 110. Advantageously, the roll 800 oflaminate 134 having security features 110 formed thereon also includesregistration marks 812 within the laminate, to assist in accuratelyregistering the security features 110 to the identification card 110.The sheet of laminate 800 in this example has been formed with dividerlines 800 thereon, to further assist the later registration andlamination to the core layer 102. The dotted lines 810 are provided forillustrative purposes only (these lines are not necessarily on thelaminate) to show where the divisions between identification documents1100 will lie. A registration mark 812 is provided on one side of thelaminate 800 also will assist when the laminate 800 is later coupled tothe core 102. The roll of laminate 800 also can include guides 810 forcutting or dicing apart of the identification documents 100.

Refer again to FIG. 7, which provides an illustrative diagram of a firstcentral issue card production system 500 that can be used to produce theidentification document 100 of FIG. 1, in accordance with one embodimentof the invention. The system 500 includes an imaging system 505,laminator and die cutter system 504, and a document production andcontrol system 506.

The imaging system includes a back printer 508 for printing the backside of the card and a front printer 510 for printing the front side ofthe card. Each printer has its own high speed controller 514, 515. Thelaminate and die cutter system 504 includes a laminator 522, a diecutter 558, and a laminator/die cutter controller 553. In oneembodiment, the laminator/die cutter controller helps to implement themethod of FIG. 9.

The document production control system includes central servers 540, areport station 534, a quality control station 536, and a mailer 530. TheQC Station 536 and its associated bar code scanner (not shown) can beused by an operator to scan the bar code of a defective sheet ordocument. Keyboard entry can also be used to report or to checkdocuments and sheets.

Production of the identification document 100 document begins at theImaging System 505, where card substrates, such as preprinted TESLINsheets 516, are fed into the back printer 508. The back sides of theTESLIN sheets 516 can be customized with desired information (e.g.,restriction codes or other information unique to each document on thesheet). In addition, bar codes for tracking the documents through theproduction process can be added. As the TESLIN sheet enters the secondsection of the Imaging System 505, the front printer 510 printsappropriate portrait and signature images on the front of the documentsbased on personalized cardholder information stored in a file. The frontprinter 510 also prints the interlaced images (which, in one embodiment,comes from an interlaced image file accessible to the laminator/diecutter controller 553) on the front of the TESLIN sheets 516. Note thatsince a plurality of identification documents 100 documents are beingproduced simultaneously, the front printer 510 can print an one moreindicia for each document onto the appropriate locations of the TESLINsheets 516. The output of the front printer 510 are document sheets 550printed on the front and back.

As completed sheets accumulate in the output hopper of the ImagingSystem 505, in one embodiment, an operator performs a visual inspectionand transfers the completed sheets to the input hopper of theLaminating/Die-Cutting System 504. Any sheets failing visual inspectioncan be brought to the QC station 536 where their bar code is scanned andproduction of a replacement automatically ordered. The failed sheets arethen destroyed.

When the document sheets 550 are about to enter theLaminating/Die-Cutting System 504, automatic scanners confirm that thefront and back sheets 550 match, that sheets 550 have not stucktogether, and that the sheets 550 are right side up. After the scanningprocess, the laminator 522 applies the desired laminate material (e.g.,polyester) on both sides (front and back) material to all sheets to forma continuous web of laminated sheets (the laminate material wouldinclude the security features 110, as shown in FIG. 8). In at least oneembodiment, registration marks printed on one or both sides of thesheets 550 help to precisely orient the laminate so that the securityfeature 110 feature is correctly aligned to at least partially overlayvariable indicia 114 formed on the identification document 100.

The web of laminated sheets leaves the laminator 522 and then passesinto the die cutter 558, which cuts the sheet into individual documents.After the identification documents 100 documents are produced and givena final quality control inspection, they are fed into the mailer 530.The mailer prints the applicant's address on the card holder and insertsthe ID document into the holder. The holder is then inserted into anenvelope for mailing

FIG. 9 is a flow chart of a first method for manufacturing theidentification document 100 document of FIG. 1 using the system of FIG.7, in accordance with one embodiment of the invention. The detaileddescription of these method steps already has been done in connectionwith the description accompanying FIGS. 9 and 13, and is not repeatedhere.

As mentioned previously, the security feature 110 also can be “stamped”or embossed onto the identification documents 100 prior to lamination.FIG. 10 is an illustrative diagram showing how the central issueproduction system of FIG. 7 could be altered to accommodate astamping/embossing process. A stamper 551 is disposed in the processafter printing and before lamination by the laminator 522. The securityfeature 110 is applied to the identification document after is itprinted, but prior to lamination. All other process steps aresubstantially the same as described for FIG. 7. FIG. 11 is a flow chartof the method used in connection with FIG. 11.

Digital Watermarking

In one embodiment of the invention, we embed a steganographic code intothe security feature 10. The steganographic code can be embedded in theoptically variable layer 116, the first covert layer 112, and/or thesecond covert layer 118. It is particularly advantageous to embed thesteganographic code into a graphical image that may be formed in any ofthese three layers. The code can be embedded in the master image, e.g.,a facial image. Or the code can be embedded in perceptually significantfeatures, e.g., facial outlines, hair, etc. that are able to survive theprocessing described herein. We also envision that steganographic codecan, of course, be embedded into either or both of the variable data 114portrait image and/or the ghost image 122.

One form of steganographic encoding is digital watermarking. Digitalwatermarking is a process for modifying physical or electronic media toembed a machine-readable code into the media. The media may be modifiedsuch that the embedded code is imperceptible or nearly imperceptible tothe user, yet may be detected through an automated detection process. Insome embodiments, the identification document includes two or moredigital watermarks.

Digital watermarking systems typically have two primary components: anencoder that embeds the digital watermark in a host media signal, and adecoder that detects and reads the embedded digital watermark from asignal suspected of containing a digital watermark (a suspect signal).The encoder embeds a digital watermark by altering the host mediasignal. The reading component analyzes a suspect signal to detectwhether a digital watermark is present. In applications where thedigital watermark encodes information, the reader extracts thisinformation from the detected digital watermark. The reading componentcan be hosted on a wide variety of tethered or wireless reader devices,from conventional PC-connected cameras and computers to fully mobilereaders with built-in displays. By imaging a watermarked surface of thecard, the watermark's “payload” can be read and decoded by this reader.

Several particular digital watermarking techniques have been developed.The reader is presumed to be familiar with the literature in this field.Some techniques for embedding and detecting imperceptible watermarks inmedia signals are detailed in the assignee's co-pending U.S. patentapplication Ser. No. 09/503,881, U.S. Pat. No. 6,122,403 and PCT patentapplication PCT/JUS02/20832, which are each herein incorporated byreference.

In one embodiment, the watermark embedded in the image may include apayload or message. The message may correspond, e.g., to the ID documentnumber, printed information, issuing authority, biometric information ofthe bearer, and/or database record, etc. The watermark embedded in theimage may also include an orientation component, to help resolve imagedistortion such as rotation, scaling and translation. In at least oneembodiment of the invention, we embed two or more watermarks in the OVDimage.

In further embodiments, the watermark embedded in the image correspondsto information printed elsewhere on the identification document 100, orto information carried by a second watermark embedded elsewhere on theidentification document 100 (e.g., background pattern, fixed indicia106, etc.). More techniques for digital watermarks and ID cards can befound in Digimarc's U.S. Provisional Patent application No. 60/421,254,U.S. patent application Ser. No. 10/094,593, and in U.S. Pat. No.5,841,886. Each of these patent documents is incorporated herein byreference. We expressly contemplate that the techniques disclosed inthis application can be combined with the aspects of the presentinvention.

Concluding Remarks

Having described and illustrated the principles of the technology withreference to specific implementations, it will be recognized that thetechnology can be implemented in many other, different, forms, and inmany different environments.

The technology disclosed herein can be used in combination with othertechnologies. Also, instead of ID documents, the inventive techniquescan be employed with product tags, product packaging, labels, businesscards, bags, charts, smart cards, maps, labels, etc., etc. The term IDdocument is broadly defined herein to include these tags, maps, labels,packaging, cards, etc.

It should be appreciated that while FIG. 1 illustrates a particularspecies of ID document—a driver's license—the present invention is notso limited. Indeed our inventive methods and techniques apply generallyto all identification documents defined above. Moreover, our techniquesare applicable to non-ID documents, e.g., such as printing or formingcovert images on physical objects, holograms, etc., etc. Further,instead of ID documents, the inventive techniques can be employed withproduct tags, product packaging, business cards, bags, charts, maps,labels, etc., etc., particularly those items including providing anon-visible indicia, such as an image information on an over-laminatestructure. The term ID document is broadly defined herein to includethese tags, labels, packaging, cards, etc. In addition, while some ofthe examples above are disclosed with specific core components, it isnoted that-laminates can be sensitized for use with other corecomponents. For example, it is contemplated that aspects of theinvention may have applicability for articles and devices such ascompact disks, consumer products, knobs, keyboards, electroniccomponents, decorative or ornamental articles, promotional items,currency, bank notes, checks, etc., or any other suitable items orarticles that may record information, images, and/or other data, whichmay be associated with a function and/or an object or other entity to beidentified.

It should be understood that while our some of our detailed embodimentsdescribed herein use infrared, UV, and/or thermachromic inks and/or dyesby way of example, the present invention is not so limited. Ourinventive techniques and methods can be used with other types offluorescing and/or covert inks and dyes as well.

It should be appreciated that the methods described above with respectto FIGS. 1-11, as well as the methods for implementing and embeddingdigital watermarks, can be carried out on a general-purpose computer.These methods can, of course, be implemented using software, hardware,or a combination of hardware and software. Systems and methods inaccordance with the invention can be implemented using any type ofgeneral purpose computer system, such as a personal computer (PC),laptop computer, server, workstation, personal digital assistant (PDA),mobile communications device, interconnected group of general purposecomputers, and the like, running any one of a variety of operatingsystems. We note that some image-handling software, such as Adobe'sPrintShop, as well as image-adaptive software such as LEADTOOLS (whichprovide a library of image-processing functions and which is availablefrom LEAD Technologies, Inc., of Charlotte, N.C.) can be used tofacilitate these methods, including steps such as providing enhancedcontrast, converting from a color image to a monochromatic image,thickening of an edge, dithering, registration, etc. An edge-detectionalgorithm may also be incorporated with, or used in concert with, suchsoftware. Computer executable software embodying aspects of theinvention can be stored on a computer readable media, such as adiskette, removable media, DVD, CD, hard drive, electronic memorycircuit, etc.).

It should be understood that, in the Figures of this application, insome instances, a plurality of system elements or method steps may beshown as illustrative of a particular system element, and a singlesystem element or method step may be shown as illustrative of aplurality of a particular systems elements or method steps. It should beunderstood that showing a plurality of a particular element or step isnot intended to imply that a system or method implemented in accordancewith the invention must comprise more than one of that element or step,nor is it intended by illustrating a single element or step that theinvention is limited to embodiments having only a single one of thatrespective elements or steps. In addition, the total number of elementsor steps shown for a particular system element or method is not intendedto be limiting; those skilled in the art will recognize that the numberof a particular system element or method steps can, in some instances,be selected to accommodate the particular user needs.

To provide a comprehensive disclosure without unduly lengthening thespecification, applicants hereby incorporate by reference each of theU.S. patent documents referenced above.

The technology and solutions disclosed herein have made use of elementsand techniques known from the cited documents. Other elements andtechniques from the cited documents can similarly be combined to yieldfurther implementations within the scope of the present invention. Thus,for example, single-bit watermarking can be substituted for multi-bitwatermarking, technology described as using imperceptible watermarks orencoding can alternatively be practiced using visible watermarks(glyphs, etc.) or other encoding, local scaling of watermark energy canbe provided to enhance watermark signal-to-noise ratio withoutincreasing human perceptibility, various filtering operations can beemployed to serve the functions explained in the prior art, watermarkscan include subliminal graticules to aid in image re-registration,encoding may proceed at the granularity of a single pixel (or DCTcoefficient), or may similarly treat adjoining groups of pixels (or DCTcoefficients), the encoding can be optimized to withstand expected formsof content corruption, etc.

Thus, the exemplary embodiments are only selected samples of thesolutions available by combining the teachings referenced above. Theother solutions necessarily are not exhaustively described herein, butare fairly within the understanding of an artisan given the foregoingdisclosure and familiarity with the cited art. The particularcombinations of elements and features in the above-detailed embodimentsare exemplary only; the interchanging and substitution of theseteachings with other teachings in this and the incorporated-by-referencepatent documents are also expressly contemplated.

In describing the embodiments of the invention illustrated in thefigures, specific terminology is used for the sake of clarity. However,the invention is not limited to the specific terms so selected, and eachspecific term at least includes all technical and functional equivalentsthat operate in a similar manner to accomplish a similar purpose.

1. A security feature, comprising: a first covert layer comprising afirst covert material that is not visible to a human eye under exceptunder a first condition, the first covert layer further comprising amaterial constructed and arranged to produce, upon an attemptedintrusion into any part of the security feature, a first effect that isvisible at least under the first condition; an optically variable layercomprising an optically variable material and having first and secondsides, the first side being disposed adjacent the first covert layer,the optically varying layer being constructed and arranged to cover atleast a portion of the first covert layer; and a second covert layerdisposed adjacent to the second side of the optically variable layer,the second covert layer being constructed and arranged to cover at leasta portion of the optically variable layer, the second covert layercomprising a second covert material that is visible to the human eyeonly at a second condition.
 2. The security feature of claim 1 whereinthe first effect comprises at least one of damaging breaking, cracking,rupturing, splitting, fracturing, splintering, changing color, changingtexture, shattering, and destroying, of the first layer upon anattempted intrusion into any part of the security feature.
 3. Thesecurity feature of claim 1, wherein the second covert materialcomprises at least one of an infrared, an ultraviolet, and athermachromic material.
 4. The security feature of claim 1 wherein thesecond condition comprises at least one of a predetermined wavelength oflight in the infrared range, a predetermined wavelength of light in theultraviolet range, and a predetermined temperature.
 5. The securityfeature of claim 1 wherein the first covert material comprises at leastone of an infrared pigment, an ultraviolet pigment, and a thermachromicpigment.
 6. The security feature of claim 1 wherein the first conditioncomprises at least one of a predetermined wavelength of light in theinfrared range, a predetermined wavelength of light in the ultravioletrange, and a predetermined temperature.
 7. The security feature of claim1, wherein the optically variable material comprises a polymeric liquidcrystal.
 8. The security feature of claim 1, wherein the second covertlayer comprises an adhesive selected to adhere the security feature toan identification document.
 9. The security feature of claim 1 whereinthe resultant security feature comprises first and second sides and,when viewed from a first side of the security feature, the opticallyvariable layer substantially covers the first covert layer.
 10. Thesecurity feature of claim 1 wherein the resultant security featurecomprises first and second sides and, when viewed from a first side ofthe security feature, the second covert layer substantially covers thefirst optically variable layer.
 11. The security feature of claim 9wherein the resultant security feature comprises first and second sidesand, when viewed from a first side of the security feature, the secondcovert layer substantially covers the first optically variable layer.12. The security feature of claim 1 wherein at least one of the firstcovert layer, second covert layer, and optically variable layer furthercomprises at least one indicium.
 13. The security feature of claim 1wherein the first covert layer is operably coupled to the opticallyvariable layer and is constructed and arranged such that an attemptedintrusion into the first covert layer causes damage to at least one ofthe first covert layer and the optically variable layer.
 14. Thesecurity feature of claim 1 wherein ADVANTAGE is used for at least oneof the optically variable layer and the first covert layer.
 15. Thesecurity feature of claim 1 wherein the first and second covert layersand the optically variable layer are constructed and arranged such thatan attempted intrusion into the security feature causes damage to atleast a portion of at least one layer of the first covert layer, secondcovert layer, and optically variable layer.
 16. The security feature ofclaim 15 wherein the damage is substantially visible to the naked eyewhen the damaged layer is subject to an appropriate condition thatnormally would enable the naked eye to see the layer before the layerwas damaged.
 17. An identification document, comprising a core layerhaving first and second sides; a security feature having first andsecond sides, the and having a first side being operably coupled to thefirst side of the core layer, the security feature comprising: a firstcovert layer comprising a first covert material that is not visible to ahuman eye under except under a first condition, the first covert layerfurther comprising a material constructed and arranged to produce afirst effect that is visible at least under the first condition upon anattempted intrusion into the first covert layer; an optically variablelayer comprising an optically variable material and having first andsecond sides, the first side being disposed adjacent the first covertlayer, the optically varying layer being constructed and arranged tocover at least a portion of the first covert layer; and a second covertlayer disposed adjacent to the second side of the optically variablelayer, the second covert layer being constructed and arranged to coverat least a portion of the optically variable layer, the second covertlayer comprising a second covert material that is visible to the humaneye only at a second condition; and a first laminate layer operablycoupled to the second side of the security feature.
 18. Theidentification document of claim 17, wherein the core layer has at leastone indicium formed thereon and the security feature is disposed so asto overlay at least a portion of the indicium.
 19. The identificationdocument of claim 18, wherein the indicium is at least one of a variableand a fixed indicium.
 20. The identification document of claim 17wherein the second covert layer comprises at least one of a laminate, anadhesive, and a coating capable of securing at least a portion of thesecurity feature to the core layer.
 21. The identification document ofclaim 17 wherein the laminate layer substantially seals the securityfeature to the core layer.
 22. The security feature of claim 17 whereinthe laminate, core layer, first and second covert layers and theoptically variable layer are constructed and arranged such that anattempted intrusion into the security feature causes damage to at leasta portion of at least one layer of the laminate layer, first covertlayer, second covert layer, optically variable layer, and core layer.23. The security feature of claim 17 wherein the core layer comprises atleast one of polycarbonate, TESLIN, TYVEC, MYLAR, MELINEX, polyolefin,polyester, polycarbonate, polystyrene, cellulose ester, polyolefin,polysulfone, polyvinyl chloride (PVC), polyethylene, polypropylene, andpolyamide, amorphous polymer, and biaxially oriented polymer.
 24. Theidentification document of claim 17 wherein the laminate layer comprisesat least one of polyester, polycarbonate, polystyrene, cellulose ester,polyolefin, polysulfone, polyvinyl chloride (PVC), polyethylene,polypropylene, and polyamide, amorphous polymer, and biaxially orientedpolymer.
 25. The identification document of claim 17, wherein the secondcovert material comprises at least one of an infrared pigment, anultraviolet pigment, and a thermachromic pigment.
 26. The identificationdocument of claim 17 wherein the second condition comprises at least oneof a predetermined wavelength of light in the infrared range, apredetermined wavelength of light in the ultraviolet range, and apredetermined temperature.
 27. The identification document of claim 17wherein the first covert material comprises at least one of an infraredpigment, an ultraviolet pigment, and a thermachromic pigment.
 28. Theidentification document of claim 17 wherein the first conditioncomprises at least one of a predetermined wavelength of light in theinfrared range, a predetermined wavelength of light in the ultravioletrange, and a predetermined temperature.
 29. The identification documentof claim 17, wherein the optically variable material comprises apolymeric liquid crystal.
 30. A method of making an identificationdocument, comprising: providing a first laminate layer having first andsecond sides; disposing the first side of a first covert layer havingfirst and second sides adjacent to the first side of a the firstlaminate layer; arranging a first side of an optically variable layerhaving first and second sides adjacent to the second side of the firstcovert layer; placing a first side of a second covert layer having firstand second sides adjacent to the second side of the optically variablelayer; aligning a first side of a core layer having first and secondsides to the second side of the second covert layer; and fixedlyattaching together the first laminate layer, first covert layer,optically variable layer, second covert layer, and core layer.
 31. Themethod of claim 31 further comprising forming at least one indicium onthe core layer.
 32. The method of claim 32 wherein the indicium isformed on the core layer before the core layer is fixedly attached tothe other layers.
 33. A security feature, comprising: a first layer ofADVANTAGE material, the first layer having first and second sides; and alayer of infrared material coating at least the first side of theADVANTAGE material.
 34. An identification document, comprising: a layerof ADVANTAGE material, the layer having first and second sides; a corelayer having first and second sides; a layer of adhesive materialapplied to at least the first side of the layer of ADVANTAGE materialand coupling at least a portion of the ADVANTAGE material to the firstside of the core layer, the adhesive material comprising an infraredmaterial; and a substantially translucent layer of laminate disposed atthe second side of the ADVANTAGE layer and along at least a portion ofthe first side of the core layer, the laminate substantially sealing thelayer of ADVANTAGE to the core layer.
 35. The identification document ofclaim 34, wherein the core layer further comprises an indicium formedthereon and wherein the layer of ADVANTAGE is positioned to overlay atleast a portion of the indicium.